Term
The least expensive way to make alkenes on a large scale is by the __________ __________ of petroleum: heating a mixture of alkanes in the presence of a catalyst (usually __________).
Alkenes are formed by __________ __________ to give an alkene and a shortened alkane. |
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Definition
1) Catalytic cracking
2) Aluminosilicates
3) Bond cleavage |
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Term
| __________ is used primarily to make small alkenes, up to about six carbon atoms. |
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Definition
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Term
| Since the products are always mixtures, __________ __________ is unsuitable for laboratory synthesis of alkenes. |
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Definition
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Term
| __________ is the removal of H2 from a molecule, just the reverse of hydrogenation. |
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Definition
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Term
| __________ of an alkane gives an alkene; this reacting has an unfavorable __________ change but a favorable __________ change. |
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Definition
1) Dehydrogenation
2) Enthalpy
3) Entropy |
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Term
The hydrogenation of alkenes is __________, with values of delta H around -80 to -120kJ/mol.
Therefore, dehydrogenation is __________ and has an unfavorable (__________) value of delta H.
The entropy change for dehydrogenation is strongly __________, however, because one alkane molecule and converted into two molecules, and two molecules are more disordered than one.
At sufficiently high temperatures, __________ is favored. |
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Definition
1) Exothermic
2) Endothermic
3) Positive
4) Favorable
5) Dehydrogenation |
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